解析 flutter 时如何等待网站上的微调器

问：

我能够使用选择器从站点接收数据，但是解析器每次更新都会输出多个结果，我对此进行了更正，使其仅接收 1 个结果，但是站点内部的微调器干扰了，我怎么能等待它关闭？

var result = await controller.evaluateJavascript(source: """
                          
  var spinner = document.querySelector('body > div.main_app > div:nth-child(6) > div.loader > div');
  var spinnerStyle = window.getComputedStyle(spinner);
  var spinnerVisible = spinnerStyle && spinnerStyle.visibility !== 'hidden' && spinnerStyle.display !== 'none';
  spinnerVisible;
""");
                          debugPrint('loaded');
                          spinnerVisible = (result == 'true');

我尝试了很多东西，这是我尝试过的方法之一

child:Scaffold( backgroundColor: Colors.black54,
            body: Column(children: <Widget>[
            Expanded(
            child: Stack(
              children: [
                const SizedBox(height: 60),
                // Row( children: <Widget>[
                //     _buildProgressBar(),]),
                  InAppWebView(
                    key: webViewKey,
                    initialUrlRequest:
                    URLRequest(url: WebUri("https://sitename")),
                    initialSettings: settings,
                    pullToRefreshController: pullToRefreshController,


                    onWebViewCreated: (InAppWebViewController controller) {
                      webViewController = controller;
                      // contextMenu.menuItems.add(value)

                    },
                    onUpdateVisitedHistory: (webViewController, url, isReload) async {

                    },
                    // onJsBeforeUnload: ,
                    // onLoadStart: (webViewController, url){
                    //
                    // },
                    onLoadStop: (controller, url) async {
                      //pullToRefreshController?.endRefreshing();

                      // contextMenu.menuItems.add(ContextMenuItem(id: 2, title: "tttt", action: () async{
                      //   controller.evaluateJavascript(source: """reply-tooltip.tooltip.flipped.reverse""");
                      // }));
                    },
                    onReceivedError: (controller, request, error) {
                      pullToRefreshController?.endRefreshing();
                    },
                    onProgressChanged: (controller, progress) async {
                      if (progress == 100) {
                        pullToRefreshController?.endRefreshing();
                        if ("https://fixuber.beeline.kz/installer/installersOrders/" != controller.getUrl().toString()){
                          Future<String?> waitForContentLoaded(InAppWebViewController controller) async {
                            bool spinnerVisible = true;
                            String? pageContent;
                            final js = "var progressBar = document.querySelector('body > div.main_app > div.blur'); if(progressBar) {if(progressBar.style.display === 'none') {true;} else {false;}} else {false;}";
                            final isProgressBarHidden = await controller.evaluateJavascript(source: js);

                            if (isProgressBarHidden == "true") {
    String html = await webViewController?.evaluateJavascript(source: "document.documentElement.outerHTML");
    RegExp exp = RegExp(r'<div.*?class="order_id">(.*?)</div>');
    Iterable<RegExpMatch> matches = exp.allMatches(html);
    List<String> spanList = [];
    for (RegExpMatch match in matches){
    spanList.add(match.group(1)!);
    debugPrint(match.group(1)!);
    debugPrint("its work top");
    }
    debugPrint(spanList.last);
                            }
                              var result = await controller.evaluateJavascript(source: """
                              
      var spinner = document.querySelector('body > div.main_app > div:nth-child(6) > div.loader > div');
      var spinnerStyle = window.getComputedStyle(spinner);
      var spinnerVisible = spinnerStyle && spinnerStyle.visibility !== 'hidden' && spinnerStyle.display !== 'none';
      spinnerVisible;
    """);
                              debugPrint('loaded');
                              spinnerVisible = (result == 'true');


                            pageContent = await controller.evaluateJavascript(source: "document.documentElement.outerHTML");

                            return pageContent;
                          }
                          String html = await webViewController?.evaluateJavascript(source: "document.documentElement.outerHTML");
                          // RegExp exp = RegExp(r'<div[^>]*class="order_id"[^>]*>(.*?)<\/div>');
                          // RegExp exp = RegExp(r'<div.*?class="order_id">(.*?)</div>');
                          RegExp checker = RegExp(r'<div.*?class="status--success">(.*?)</div>');
                          Iterable<RegExpMatch> checkerMatch = checker.allMatches(html);
                          List<String> checkerList = [];
                          Iterable<RegExpMatch> matches = checker.allMatches(html);
                          // Iterable<RegExpMatch> matches = exp.allMatches(html);
                          List<String> spanList = [];
                          if (checkerList.length == 0){
                            debugPrint("not match");
                          } else {
                          for (RegExpMatch match in matches){
                            if(match.group(1)!=null){
                            spanList.add(match.group(1)!);}
                            debugPrint(match.group(1)!);debugPrint("!its work bot");
                          }
                          debugPrint(spanList.last);debugPrint("its work bot");}}
                        //this.progress = progress / 100;
                      }
                    },
                  ),
            ]),
            ),
            ])));

这基本上是我所有的代码，如果你帮忙，我会很高兴的